When forklifts are used in an industrial environment such as a factory or a warehouse situation, they usually occupy a space that is populated not only with forklifts but with other moving things as well. These can comprise a wide variety of moving objects such as powered and unpowered utility carts, bicycles, golf carts and even people. Wherever there are moving objects such as these, there is always a danger of collision between them. Particularly severe collisions can happen when the moving objects are massive, such as when forklifts collide, and even lethal damage can occur if a person is involved in a collision.
The danger of collisions is manifest at intersections on a factory or warehouse floor, especially, when views are inhibited by items adjacent the intersections that obscure oncoming traffic approaching the intersections.
Prior art for warning of or seeing approaching traffic at intersections has included traffic signals, various mirror arrangements for observing traffic, floor embedded sensors for triggering warnings, auditory warning systems, and sensors distributed around the areas of approach to intersections. These have been used to trigger various warning devices from signs to whistles.
Installation of these systems is often expensive and time consuming. The installation usually requires significant wiring over a plurality of approaches and a central control unit with the wiring often subject to damage in the industrial environment. In addition the distributed sensors on which they depend are easily blocked or damaged due to their distribution around the area of the intersection with some of them necessarily disposed at low levels where they can easily be hit or damaged by activities occurring in the industrial environment.
A reliable and robust apparatus for detecting and warning of the presence of traffic that approaches the intersection outside the line of sight of one approaching the intersection is needed. This system should be able to detect and distinguish between the kind of traffic that is approaching the intersection, the sizes of objects approaching the intersection and various properties of the objects approaching such as speed and composition. The apparatus should further be able to distinguish whether the traffic is approaching or departing the intersection. The apparatus should then be able to warn of the approach of objects that might be out of the line of sight of one approaching the intersection and designate the positions of the other approaching traffic.
Further, the apparatus should be easily installable requiring little time or skill on the part of the installer. Most desirable would be a single integrated unit not requiring the disposition of various parts of the apparatus about the intersection. Particularly, extensive on-site wiring of detectors sensors and the like should be avoided.
The apparatus should offer direct visual identification of the traffic approaching the intersection. This would be best accomplished by providing an image of the approaching traffic in addition to a warning even if the intersection comprises acute, right, or obtuse angles between intersecting pathways.
Those who routinely work in or manage an industrial situation where traffic must pass through intersections will recognize that such improvements in intersection warning systems are needed.